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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>类的基础知识</title>
</head>
<body>
    
</body>
<script>
        
        let a = 'name';
        let obj = {};
         obj[a] = 'jack'
         console.log(obj)
</script>
</html>